Documentation Follow-up Work

[peytondmurray]

After the recent change to documentation hosting and format, there is some follow up work:

• The "Run in Google Colab" etc buttons found in the guides need to be restyled as actual buttons instead of links. See https://tensorflow.github.io/tfx/tutorials/tfx/gcp/vertex_pipelines_simple/
• Main API reference landing page is empty. We need some links for the various child pages here: https://tensorflow.github.io/tfx/api/v1/
• Addons page is broken: https://tensorflow.github.io/tfx/addons/
• The "TFX for Mobile" page is broken: https://tensorflow.github.io/tfx/tutorials/tfx_for_mobile. However https://tensorflow.github.io/tfx/tutorials/tfx/tfx_for_mobile/ is not; not sure which one is the correct one, or if there should be two?
• Remove the TF logo; visibility is not high enough

cc @rcrowe-google for visibility.

[smokestacklightnin]

Addons page is broken: https://tensorflow.github.io/tfx/addons/

There is a PR for the Addons page: #6913

[smokestacklightnin]

The "TFX for Mobile" page is broken: https://tensorflow.github.io/tfx/tutorials/tfx_for_mobile. However https://tensorflow.github.io/tfx/tutorials/tfx/tfx_for_mobile/ is not; not sure which one is the correct one, or if there should be two?

Fixed in this commit

[smokestacklightnin]

• Main API reference landing page is empty. We need some links for the various child pages here: https://tensorflow.github.io/tfx/api/v1/

Fixed in this commit